1. Field
Embodiments relate to a battery pack.
2. Description of the Related Art
As the number of gasoline vehicles has increased, the amount of vehicle exhaust emission has also increased. Vehicle exhaust emission includes large amounts of harmful substances, such as nitrogen oxide due to combustion, carbon monoxide or hydrocarbon due to imperfect combustion, or the like, and is recognized as a serious environmental pollution problem. As fossil fuels are anticipated to be significantly diminished in the not too distant future, development of next generation energy sources and hybrid electric vehicles have become important issues. In terms of commercializing hybrid electric vehicles, mileage of such vehicles is determined by battery performance. Currently, however, batteries do not have enough electrical energy for powering hybrid electric vehicles for a desirable period of time or mileage. If vehicles use energy sources such as gasoline, light oil, gas, or the like, the vehicles may quickly refuel in filling stations or gas charging stations. However, even when an electric charging station is available, it takes a long time to charge a hybrid electric vehicle, which is an obstacle to commercialization. Thus, with regard to hybrid electric vehicles, improving battery performance, compared to other technologies regarding hybrid electric vehicles, is recognized as an important problem.